Eastern Pacific Tropical Weather Discussion (Text)

000
AXPZ20 KNHC 021605
TWDEP
TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN AUG 02 2015
TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND
METEOROLOGICAL ANALYSIS.
BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1545 UTC.
...TROPICAL WAVES...
THE SOUTHERN PORTION OF A TROPICAL WAVE HAS ENTERED THE AREA
ALONG 94W AND N OF 14N...MOVING W AT 15 KT. NO DEEP CONVECTION
IS NOTED WITH THIS WAVE. ONLY WEAK ISOLATED SHOWERS AND TSTMS
ARE WITHIN 30 NM OF THE WAVE AXIS. THE WAVE IS FORECAST TO
GRADUALLY LOSE ITS AFTER 48 HOURS.
A TROPICAL WAVE AXIS IS ANALYZED ALONG 113W FROM 06N-16N
16N...MOVING W NEAR 16 KT. FIRST VISIBLE SATELLITE IMAGERY SHOWS
RATHER BROAD NE TO SE FLOW OF THE LOW-LEVEL CLOUD FIELD IN AN
INVERTED V-SHAPE PATTERN FROM ABOUT 09N TO 16N BETWEEN 108W AND
118W AS TYPICALLY SEEN WITH ATLANTIC TROPICAL WAVES. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 180 NM E OF THE
WAVE FROM 10.5N TO 13N...AND WITHIN 120 NM W OF THE WAVE FROM
12.5N TO 15N. THE GLOBAL MODELS SUGGEST THAT A CLOSED LOW CENTER
WILL FORM ALONG THE WAVE NEAR 10N TODAY...AND TRACK IN A GENERAL
WNW MOTION THROUGH TUE. EXPECT DEEP CONVECTION TO INCREASE ALONG
THE WAVE AND NEAR FUTURE LOW.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
A RATHER SHORT MONSOON TROUGH AXIS EXTENDS W OFF THE PACIFIC
COAST OF COSTA RICA AT 09.5N85W AND CONTINUES TO NEAR 08N90W
WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO AN ITCZ AXIS
WHICH CONTINUES WNW TO 09N100W TO JUST E OF THE TROPICAL WAVE
ALONG 113W. IT THEN RESUMES AT 09N115W AND DIPS TO THE SW TO
07N126W TO 8N140W. SCATTERED STRONG CONVECTION IS WITHIN 60 NM
OF THE AXIS BETWEEN 122W-127W. SCATTERED MODERATE/ISOLATED
STRONG CONVECTION IS WITHIN 180 NM S OF THE AXIS BETWEEN 103W-
106W AND BETWEEN 109W-117W. SIMILAR CONVECTION IS WITHIN 60 NM
OF THE AXIS BETWEEN 127W-129W... AND WITHIN 120 NM S OF THE AXIS
BETWEEN 135W AND 140W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS SEEN TO THE SE
OF THE MONSOON TROUGH OVER AN AREA FROM 04N TO 07N E OF 80W
TO JUST INLAND THE COAST OF COLOMBIA.
...DISCUSSION...
UPPER LEVELS...
SW MODERATE TO STRONG WINDS ALOFT ASSOCIATED WITH A BROAD TROUGH
JUST W OF THE NW PART OF THE AREA ARE ADVECTING OVERCAST CIRRUS
CLOUDS FROM THE OUTFLOW OF HURRICANE GUILLERMO...CENTERED NEAR
14N144W...INTO THE FAR WESTERN PART OF THE AREA TO THE N OF 13N
AND W OF 134W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS
SEEN JUST ALONG 140W FROM 14N TO 17N W OF 139W. THE ATMOSPHERE
REMAINS VERY MOIST IN THE UPPER LEVELS...EXCEPT FOR A SUBSIDENT
AREA SUPPORTING DRY AND STABLE ENVIRONMENTAL CONDITIONS OVER THE
CENTRAL PORTION OF THE AREA N OF 10N BETWEEN 120W AND 129W.
AT THE SURFACE...
A WEAK 1018 MB HIGH CENTER IS NEAR 28N128W WITH A RIDGE
EXTENDING SE TO NEAR 21N118W. THE PRES GRADIENT BETWEEN THE
RIDGE AND THE BAJA CALIFORNIA THERMAL TROUGH WILL SUPPORT
NORTHWESTERLY 15-20 KT FLOW...AS INDICATED IN A RECENT WINDSAT
PASS...WITHIN ABOUT 150 NM OF THE BAJA CALIFORNIA PENINSULA
THROUGH TUE WITH SEAS OF 5-7 FT.
GULF OF PAPAGAYO...NE-E WINDS 15-20 KT WINDS CURRENTLY THROUGH
THE GULF ARE FORECAST TO BEGIN TO INCREASE LATE TONIGHT INTO
EARLY MON MORNING AS THE PRES GRADIENT IN THE VICINITY TIGHTENS.
THIS COMBINED WITH THE NOCTURNAL DRAINAGE FLOW WILL ALLOW FOR
THESE WINDS TO INCREASE TO 20-25 KT BEGINNING LATE TONIGHT. GFS
MODEL INDICATES THAT THE WINDS DIMINISH AGAIN TO 15-20 KT MON
AFTERNOON...AND INCREASE AGAIN LATE MON NIGHT INTO EARLY ON TUE
WITH THE AREA OF 20-25 KT WINDS EXPANDING. SEAS ARE FORECAST TO
BE IN THE 7-9 FT RANGE AS THE 20-25 KT DEVELOP...HOWEVER SEAS OF
7-8 FT WILL PROPAGATE WSW FROM THE GULF TO NEAR 92W BY TUE
AFTERNOON.
$$
AGUIRRE